I have been tring to quit smoking.

have been ~~~~~~ing. 

1/ 이전에 했던 동작 및 상태의 지속,

   for or since 와 같이 사용하여 시간의 길이 표현

 - Eddie has been talking to her wife on the for about 2hours. 

 - i have been working this project since 9am this morning. 

 - i have been waiting for the train for over 30 mins. 

 - how long have you been doing this kind of job ?

2/ 근래 오랜시간을 진행중. 

 - I have been tring to quit smoking. 

 - I have been consideration transferring to another school rescently. 

 - I have been thinking about divorce

3/ 방금전 끝난 동작

 - Itsbeen raining. so.